Dr. Brown's Uniquely Designed Options Plus Natural Flow Stage 4 Wide Neck Bottle features a fast-flowing nipple designed for more advanced infants who prefer a faster milk flow. The breast-like shape promotes a better grip on the baby for a more natural feeding experience. The nipple that has been designed in collaboration with doctors has a split shape and high-quality soft silicone to provide a more comfortable feeding experience and help prevent baby confusion due to the nipple. Perfect for switching between breast and bottle feeding!